Ru–support interface tailoring for enhanced aerobic oxidation of 1,4-butanediol

Abstract

The selective oxidation of diol molecules to five-membered ring oxygenates is a reaction of significant practical importance. However, disentangling the trade-off of insufficient activation of reactants and adsorption of products remains challenging. Herein, we systematically demonstrate how metal–support interaction (MSI) directs the selective oxidation pathway of 1,4-butanediol (BDO), by engineering Ru catalysts on distinct supports, namely hydrotalcite (HT), silicon dioxide (SiO₂), titanium dioxide (TiO₂), and hydroxyapatite (HAP). Notably, the Ru/TiO₂ catalyst achieves exceptional performance under mild conditions, with 99% BDO conversion and 96.7% selectivity to 2-HTHF. This extraordinary performance originates from an optimally balanced metal–support interaction (MSI). Furthermore, a downshifted d-band center (−1.85 eV) coupled with strengthened key C–H and O–H bonds (as evidenced by their –ICOHP values of −7.45 and −8.41 eV, respectively), collectively facilitates efficient reactant activation and timely product desorption. Conversely, weak MSI in Ru/SiO₂ leads to insufficient BDO activation, whereas that in Ru/HAP promotes deep oxidation of 2-HTHF to γ-butyrolactone (GBL) due to overly strong interfacial adsorption of hydroxyl groups. This work elucidates the ensemble mechanism of MSI across structural, electronic, and adsorption dimensions, providing a fundamental basis for the rational design of highly selective oxidation catalysts.